Method of controlling flow of fluid from the high to the low pressure lines of a fluid-circulating system



June 30, 1925. 1,544,195

3 C. STEWART ET AL METHOD OF CONTROLLING FLOW OF FLUID FROM THE HIGH TOTHE LOW PRESSURE LINES OF A FLUID CIRCULATING SYSTEM Original Filed Dec.16, 1918 2g Ens. 7 g. 2

gmlanlozs Barf 0. Slevari. Clarence )f. Holley.

Gum

Patented June 30, 1925.

- UNITED STATES PATENT OFFICE.

BURT C. STEWART, OF BIRMINGHAM, AND CLARENCE M. HOLLEY, OF HIGHLANDPARK, MICHIGAN, ASSIGNORS, BY MESNE ASSIGNMENTS, TO THE HOOVER COM PANY,OF NORTH CANTON, OHIO, A CORPORATION OF OHIO.

METHOD OF CONTROLLING" FLOW OF FLUID FROM THE HIGH TO THE LOW PRESSURELINES OF A FLUID-CIRCULATING SYSTEM.

Original application filed December 16, 1918, Serial .No. 266,848.Divided and this application filed October 14, 1922.

To all whom it may concern:

Be it known that we, BURT C. STEWART and CLARENCE M. HoLLEY, citizens ofthe United States, residin at, respectively, Birmingham, Oakland County,and Highland Park, Wayne County, State of Michigan, have invented acertain new and useful Improvement in Methods of- Controlling F low ofFluid from the High to the Low Pressure Lines of a Fluid-CirculatingSystem, and declare the following to be a full, clear, and exactdescription of the same, such as will enable others skilled in the artto which it pertains to make and use the same, reference being had tothe accompanying drawings, which form a part of this specification.

This invention relates to method of discharging fluidl from th high tothe low pressure line of a' fluid circulating system, its object beingto provide a method whereby the fluid is discharged in such manner thatthe pressure of the low pressure side of thesystem remainspracticallyconstant.

This application is a division of our joint application for LettersPatentof the United States for automatic expansion valve, Serial No.266,848, filed December 16, 1918. The method is particularly adapted foruse in the circulating system of artificial refrigerating apparatus orother fluid circulating systems particularly in such systems as those inwhich a compressor is utilized to withdraw fluid from the low pressureside and discharge the same to the high pressure side. In some wellknown fluid circulating systems utilizing an expansion valve, thepressure of the low pressure side of the system is utilized to close thehighpressure line stopping the flow to the low pressure line until thepressure therein has been reduced to some extent. Such. methods,however, vary the pressure of'the low pressure side to a material extentas the flow to the low pressure line continues until the entire lowpressure side of the system, from the valve to the pump, is filled withfluid under pressure sufliciently great to cause closing of the highpressure line which remains closedv until the low pressure or expansionside of I Serial No. 594,497.

' a the system is again reduced to the predetermined low pressure. Thisinvention diflers particularly from such previous methods, the objectbeing to prevent any material variation in the pressure of the expansionline and to holdv the pressure therein practically constant by firstdischarging only a very small volume of fluid, in comparison to thecapacity of the expansion or low pressure side, into a chamber, thepressure of which acts to close the high pressure line and to open thelow pressure line to the chamber permitting the small volume of fluid todischarge into the low pressure side. Although such volume dischargedinto the chamber is of apressure somewhat higher than that in theexpansion side, yet, due tothe very small volume, there is practicallyno increase in the pressure of the expansion or low pressure side of thesystem. By such method the beneficial result is obtained of maintainingthe low pressure side of the system at asubstantially constant lowtemperature, which temperature by previous methods is varied to amaterial extent especially in small household installations. Greaterefficiency is attained through use of our improved method in which thetemperature of the low pressure side is maintained practically constant.

These objects and novel features of our invention may be accomplished byvarious types of mechanism, only one of which is shown in the drawingwhich is a vertical section of an expansion valve for use between thehigh and low pressure lines of a fluid circulatlng system adapted tooperate upon our improved method. 1

In the construction shown, the device consists of a lower preferablycylindrical member 1 and a cap member 2 therefor each of suchcomplemental shape as to provide a chamber therebetween. To the capmember 2 is secured a hollow stem 3 to which is to be connected the highpressure line of a circulating system, and the member 1 at the bottom isprovided with a threaded inlet 4: to which is to be attached the pipingforming part of thelow pressure side of the system. The tubular member 3is provided with a channeled extension 5 which extends downward into thechamber fbrmed between the members 1 and 2 as shown. To this tubularmember 3 at the upper end. which is shaped to receive the same, issecured a corrugated cylinder preferably formed of copper. The upper endof this cylinder is secured by soldering the same to i a shoulder formedat the upper end of the part 5and the lower end of the cylinder issecured to a hub 6" of a plate 7 as shown. This plate is preferablycylindrical in form .and to the periphery thereof is secured apractically expand or contract to an equal extent. The lower end of thepart 5 extends into the apertured hub of the plate 7 but is spaced fromthe wall thereof as indicated. This plate is provided also with anexternal hub 9 threaded to receive the threaded body of a coned valve10. This valve is provided with a lock'nut 11 and the parts 6 and 8 andtube 3 have been assembled on the part 2 of the casing, the valve is setto cause expansion to a greater or less degree of the corrugatedcylinders whereby the natural tendency of the cylinders to contracttends to hold the valve closed, and it is to be understood that the areaof the channel in the part 5 is so small that the presure exerted on theface of the valve open to the pressure line is insuflicient to expandthe cylinders 6 and 8 and open the valve to-fiow therethrough.- By theconstruction described, there is a small chamber 12 provided inside thecylinder 6 and between the cylinder and the tubular member 5, and thischamber is open to the chamber 14 formed between the plate 7 andcylinder 8, and the case lby means-of the apertures 13 formed in the hubmember 9. This chamber 14 is thus open at all times to the chamber 12and forms the first expansion chamber of the system. It is to be notedin passing, that the casing is formed of two parts 1 and 2 for thepurpose of allowing the cylinders to be assembled and the valve tobe setwhile the two parts, aredisengaged, and that in securing the partstogether by means of the bolt 15, the ring 90 provides a gasket andrevents any leakage through the interstice between the meeting surfacesof the two parts whereby the vacuum in the chamber 14 might be broken.This construction allows the several parts to be readily assembled ordisassembled. The

valve body has a valve 10 at one end and a valve 16 at the opposite endwhich extends downward through the threaded stem 4. A seat for the valve16 is provided in the threaded plug 17 in the stem 4. This plug has acentral channel 18 therethrough adapted to be closed by the valve 16,and the plug, 17 may be varied in position relative to the valve 16 byturning the same in the threaded stem and thus provide for a greater orless movement of both the valves 10 and 16. The threads in the stem andplug should be fine incharacter in order that a minute adjustment of theplug may be secured and, by such adjustment, the degree of vacuum to bemaintained in the expansion system may be varied. After the plug is onceset, however, and the system connected up, it is evident, by reason ofthe 'plug being on the interior of the piping,

that it is impossible to disarrange the valve from the exterior and thusthe disarrangement by unauthorized persons is prevented as is desirablein systems in general public use.

' The operation of the device is as follows, it being understood that apump ordinarily used with a system of this character is utilized tocompress the fluid on the pressure side of the system and to draw thefluid from the vacuum side. Vith the pump in operation in a system ofthis character involving the valve described, a vacuum is produced onthe vacuum side of the system and in the chambers 14 and 12 and thepressuretherein is reduced until the pressure of atmosphere on theoutside of the corrugated members 6 and 8 which is the chamber 20 opento atmosphere through an aperture '19 in the case 2), expands the saidcylinders and opens the valve 10. This movement of the valve 10 closesthe valve 16 and thus closes the vacuum side of the system to thechamber 14. By this arrangement, fluid under pressure will be dischargedfrom the pressure line into the chamber 14 and relieve the degree ofvacuum therein to an extent to allow the natural contraction of thecylinders 6 and 8 to again close the valve 10. The closing of the valve10 opens the chamber 14 to the vacuum side of the system, and the fluidin the chamber 14 is thus discharged into the vacuum coils and, byreason of its small volume in comparison to the capacity of the coils,is immediately expanded to its greatest extent. By this arrangement alsoand due to the fact that the chamber 14 is small in volume in comparisonto the volume of the expansion-side of the system, the degree of vacuumtherein is not. relieved by this discharge and thus, although there ispractically continual discharge of fluid from the high to the lowpressure side of the system, it is at no instant of time of such volumeasto cause mate-.

rially evident fluctuation in the degree of vacuum maintained.Furthermore, there is not a gradual expansion of fluid'when dischargedfrom thechamber but in fact the expansion is almost instantaneous, andtherefore is highly efficient as it is instantly 1n condition to take upheat. The principal object of the invention is involved in this featureof construction by means of which a small quantity of fluid underpressure is first discharged into a chamber to relieve the vacuumtherein which closes the pressure side of the system and opens thechamher to the expansion side, and this operation in practice is foundto be very rapid, the valve fluctuating so rapidly as to cause acontinuous sound.

The chamber 20 formed between the exterior of the cylinder 6 andinterior of the cylinder Sand case 2, as before stated, is open toatmosphere through the port 19.

By this arrangement airat normal temperature may enter the'chamber 20and maintain the temperature of the walls of the cylinders and plate 7,and consequently the valve 10 at such degree as to prevent congealing ofany foreign substance, as oil or other matter, at the point of dischargeinto the chamber 14. Thus, freezing of the valve on its seat isprevented. It is furthermore necessary to open this outsideof thecylinder 6 and inside of the cylinder 8 to atmosphere in order that thepressure thereof may be utilized to open the valve upon suflicientreduction in pressuretin the chamber. Further, by opening the outside ofthe cylinder to atmosphere no material temperature change takes place inthe air outside the cylinder. I

In the device illustrated the construction is such that atmosphericpressure is util-. ized in opening the high pressure line to the chamber14. So far as this method is concerned, however, means may beemployed inthe structure to require greater than atmospheric pressure to open thehigh pressure line or less than atmospheric pressure in the chamber 14to close the high pressure line, the structure here shown being moreparticularly illustrative of the method involving the two-stageexpansion described discharging a small volume of fluid from the highpressure side to a chama manner to maintain the pressure of the lowpressure line substantially constant,

which consists in expanding a relatively small volume of the fluid to apartial degree, and then introducing the partially expanded charge intothe low pressure line.

3. The method of discharging fluid from the high to the low pressureside of a fluid circulating system, which consists in first dischargingaquantity of fluid under pressure and small in volume in comparison tothe volume of the low pressure side into av small volume of the fluid.from the high pressure line to a partial degree, then opening the lowpressure line, and closing the high pressure line to the chamber bymeans of the introduced charge. i 5. The method of regulating thepressure of a fluid by controlling its fiow from the high to the lowpressure side of a fluid circulating system, which consists inrepeatedly passing relatively small volumes of fluid from the high tothe low pressure line by a-multi-stage expansion of each volume throughinfluence of the pressure of the low pressure line and regulating therapidity of I introduction to the low pressure line by in-' fluence ofthe pressure thereof.

6. The method of regulating the pressure of a fluid by controlling itsflow from the high to the low pressure side of a fluid circulatingsystem in which the fluid is mechanically withdrawn from the low pres'sure side and discharged into the high pressure side under pressure,which consists in the provision of a chambered body into' 'the lowpressure of the said low pressure 1., The method of discharging fluidfrom side a volume of fluid from the high pressure and closing the highpressure line and opening the low pressure line to the chamber byinfluence of the pressure of the introduced volume.

. 7. The method of discharging a refriger- Q ati ng fluid from the highto the low pressure side of a fluid circulating system, comprising thesteps of admitting to a chamber a quantity ofthe fluid, vaporization andinitial expansion of the fluid therein, whereby the initial expansionoperates means preventing admission of further fluid to the chamber andcauses transfer of the initially expanded fluid to the low pressure sideof the system.

8. The method ing the volatilization and expansion of a refrigeratingfluid in a plurality of stages of expansion.

0fnefrigeration compris consisting of ,volati wing and initiallyexpanding a refrigeration fluid and the subsequent admission of thevolatilized and initially expanded fluid into an expansion systerm forfurther expansion and the production of refrigeration.

10. The method of refrigeration comprising the introduction of aquantity of refrigeration fluid intoa chamber for volatilization andinitial expansion Whereby the volatilization of the fluid operates meansadmitting the initially expanded refrigerant to an expansion system forfurther expansion.

In testimony whereof, We signthis specification. K

BURT'C. STEWART. CLARENCE M. HOLLEY.

9. The method of roduci'ng refrigeration

